LINCOLNSHIRE, Ill. & SOUTH SAN FRANCISCO, Calif.--(BUSINESS WIRE)--BioSante Pharmaceuticals, Inc. (NASDAQ: BPAX) and Cell Genesys, Inc. (NASDAQ: CEGE), today announced that each will hold a special stockholders meeting on September 30, 2009 at which time stockholders will be asked to approve the previously announced merger between the companies. On June 29, 2009, BioSante and Cell Genesys entered into a definitive merger agreement by which the companies will merge in an all-stock transaction, with BioSante as the surviving company.